Before the trip starts try reviewing all the plans. A written schedule if they can read or pictures of the locations can be helpful. Describe every step including the travel arrangements. Try to include the child in preparations for the trip including packing and shopping. Describe specific reinforcers that he might like to receive during the trip for good behavior. You might even have the child select some of the reinforcers to be sure they are strong for the trip.
During the trip bring specific reinforcers and times that they may be earned or specific behaviors that might result in earning a reinforcer. During the trave time you can provide toys or activiites and reinforcers to assure that the trip goes smoothly. Also reveiew again while traveling what the itinearay will be and what is expected of the child when he arrives at the destination in order to earn reinforcers. For example, you might say "when we arrive we will greet all the relatives and tell them about the plane flight and what we did and ate on the flight!"
After arrival make sure you provide reinforcers at least daily for good behavior. Also, make sure to continue each morning to reveiw the itinary and the reinforcers. Also, during the trip make sure the child eats the food that agrees with there body and sleeps enough hours in order to prevent behavior problems. Remember prevention is crucial in order to enjoy your vacation with your child!!